1. Field of the Invention
The present invention relates to a pivot shaft mechanism, and also a pivot shaft mechanism of a camera for pivoting a rotatable grip on a camera body.
2. Description of the Related Art
A pivot shaft mechanism which includes a cylindrical member and a shaft member positioned inside the cylindrical member to be rotatably supported thereby, wherein a leaf spring for applying a frictional resistance to the cylindrical member and the shaft member therebetween is inserted in between the cylindrical member and the shaft member, is known as a conventional structure which gives a frictional resistance to a rotational shaft in a rotational direction thereof. Although this type of pivot shaft mechanism can be applied to various types of devices, it is sometimes the case that the pivot shaft mechanism is required to apply a large frictional resistance to the rotational shaft in a rotational direction thereof, especially in the case where a there is a high demand for saving space. For instance, in a camera having a rotatable grip pivoted on a camera body about a pivot shaft (rotational shaft), if the grip is made to be capable of being held at a desired angular position by the friction produced by the leaf spring, the pivot shaft mechanism can be miniaturized by a greater degree than the case where a stop device such as a click-stop mechanism is used; moreover, the angle of the grip relative to the camera body can be adjusted without going through predetermined steps. On the other hand, it is required to increase the friction produced by the leaf spring so that the pivot shaft does not rotate unintentionally by the own weight of the camera body. However, if the size or thickness of the leaf spring is increased to increase the friction produced by the leaf spring, the diameter of the pivot shaft inevitably increases, which is contrary to the demand for minimization of the camera. In this type of pivot shaft mechanism, the leaf spring easily comes out of the space between the cylindrical member and the shaft member during assembly, and accordingly, it is desirable to improve the ease of assembly of the pivot shaft mechanism.